fifo-stack – FIFO and stack implementation for package writers

A LaTeX im­ple­men­ta­tion of a com­bined FIFO Stack mod­i­fied from the
ex­ist­ing stack pack­age by Ben­jamin
Ba­yart.

The pack­age re­names the orig­i­nal’s \Push and
\Pop com­mands \FSPush and \FSPop, and
which work on the top/end of the FIFO/Stack), and adds the abil­ity
to \FSUn­shift and \FSShift from
the bot­tom (front) of the FIFO/Stack.